My life with Python trikes Mk1 , Mk1.5 , Mk2 ?

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Ok the Mk1a is now on it's wheels:-



The Mk1 front end still has it brakes cabled up at the moment.

However the Mk2 rear end also has it's SA drum brakes fitted but un-cabled yet.



Compared with Mk1 rear on the left ?

So next up is to cable the brakes up.

If all goes well then we need a rear pannier for day to day stuff and a light bar and high reflector.



Then we want some miles on it to see what it's like ?

regards Paul
 
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Looking truly awesome Paul.
I am sure its going to be great!
 
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Why is this thing constantly kicking me in the teeth ?

Now I have another problem with the brakes ? I have the brakes cabled up however one is good and one dud ?

So new parts are :- levers - cables/inners/outers - back plates

Second hand parts are :- wheels

I bought a pair of new SA brake levers [ to get a parking brake :) ] one of which came with a cable.

I fitted new levers and the supplied cable and another also new cable[ source unknown [ may be Asda ?]].

One brake has adjusted up fine and already on a dry road without the lever hitting the bars I can almost lock the wheel ...

The other one is troublesome ?

The lever pulls all the way up to the bars and only retards?

I think at first it was inching the cable locking thinkie up the cable so I removed it from the lever and tighten it with 2 spanners and tried again .

No better.

Also I seem to have a problem where the ferrule at the adjuster end is tight in the barrel so the only way to move the threaded part [ that clips in the back plate ] up or down the adjuster is to un-clip them both move it and clip them back up again.

Cable management is currently with a few reusable cable ties ?

I wonder if either the cable outer is not good enough or I have insufficient cable ties to stop flexing of the outer ?

Or there is another problem.

frustrated after a promising start ....Paul
 
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The lever pulls all the way up to the bars and only retards?
Sounds like a compressing outer sheath of poor quality. Does the brake feel "sponge-y?
 
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In a word YES
 
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Reading several threads online there is much said about long brake cable runs often being "spongie" (cable-outer getting compressed) and also a need to get the shoe to fit the curvature of the drum through usage for better and more effective braking (i.e. they have a fairly long bedding-in period (unlike disc-pads)). That being said, good quality (non-spiral wound) cable-outers as used on gear shifters, might be a better bet than the standard cheap variants. As I said to you on the phone, it is almost impossible to put the pinch-bolts on the end of the cables AND do them up with the wheel and cable-adjusters on the bike.
I take the drums off and wind the long adjuster about 3/4 of the way in, then mark where the cable inner exits the pinch-nut when sitting in the slot in the brake actuator arm with a marker-pen.
take the cable adjuster etc. off the backplate, slide the pinch nut to the marked position and do it up tight.
With the wheel/drum still off the bike assemble the adjuster and pinch nut onto the backplate and wind the adjuster in a little bit to make sure the shoes are fully retracted.
Pop the wheel on and turn the adjuster to suit.
SA Drum bubs in small rims make for very strong wheels. Decent braking and virtually maintenance free.
I hope you get it sorted Paul.
 
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Dan

Lots to think about , using 2 different cables has sort of been a mixed blessing , one side can lock the wheel up when stopping from a fair speed so that does show they can work properly and the cable runs are liveable with.

If both the cables had been the same and resulted in indifferent spongey brakes then I would have been in a real pickle not knowing what might be causing it.

After I had installed them I looked up how to adjust them , it is not how I imagined where you adjust them up tight and slacken off till the wheel spins freely ? I was coming at it from the other end and having to much slack in the inner cable before adjustment.

And the end clamp adjuster can only be secured if you have 3 plus hands and NOT have the trike frame/luguage frame in the way !!!

Done some retail therapy before I have another go...

Least I now have thongs to look at/for

Paul
 
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Crikey blimey have it fixed !

After extensive YouTube overload and talks with DannyC who has trod this path successfully before me I attacked it with renewed vigor.

Took the cable outer off only to find the black plastic feral's jammed into both the adjuster and brake lever ?

Got another new but unmarked outer and cut it to length added two steel feral's and reassembled.

Knowing a bit more about their adjustment now I move the stop down about .5" and readjusted both brakes.

Now in an emergency stop the left hand one can lock the wheel up briefly and the right hand one comes close , can't expect any more now till they are bedded in.

So small list of stuff to do before it's maiden voyage to my parents house , hopefully Monday if all goes well.

Thanks for your advice and hanging in there Paul
 
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Crikey blimey have it fixed !

After extensive YouTube overload and talks with DannyC who has trod this path successfully before me I attacked it with renewed vigor.

Took the cable outer off only to find the black plastic feral's jammed into both the adjuster and brake lever ?

Got another new but unmarked outer and cut it to length added two steel feral's and reassembled.

Knowing a bit more about their adjustment now I move the stop down about .5" and readjusted both brakes.

Now in an emergency stop the left hand one can lock the wheel up briefly and the right hand one comes close , can't expect any more now till they are bedded in.

So small list of stuff to do before it's maiden voyage to my parents house , hopefully Monday if all goes well.

Thanks for your advice and hanging in there Paul
Knew it would come good. Congrats. When they have bedded in they should be really good and the Python can fly along without fear of a grisly end.
 
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Ok that excited got up 30 mins early.

Bought me enough time to add a lumber lump on the seat and transferred the Mk1 Python Ventist seat pad over [ quicker than deploying one of the two new ones I bough last year in Holland ] moved over the pannier with tools/pump/inner tubes etc and declared it ready to go.

So of to mothers 8 miles there with 3 good hills and 4 miles home via Mansfield market place 12 miles in total.

Couple of observations :-

front end is vertical ! makes a change the Mk1 had a list to the left , now I catch my lower inner knee on the disc caliper [ however that may be on borrowed time !]
nice not to rub elbows on rear wheels as wheelbase has changed from 36" to 41"
luggage area is to big !!! by about 3-4" now if I cut and reweld the bustle to remove the excess it will have the same effect as moving the rear wheel back by the same distance. It will make the trike shorter AND move the load further over the rear wheels so improving the traction win win.
Ride seems better [ longer wheel base ] but to be honest that is subjective and 12 miles are not many !

regards Paul
 
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Ok that excited got up 30 mins early.

Bought me enough time to add a lumber lump on the seat and transferred the Mk1 Python Ventist seat pad over [ quicker than deploying one of the two new ones I bough last year in Holland ] moved over the pannier with tools/pump/inner tubes etc and declared it ready to go.

So of to mothers 8 miles there with 3 good hills and 4 miles home via Mansfield market place 12 miles in total.

Couple of observations :-

front end is vertical ! makes a change the Mk1 had a list to the left , now I catch my lower inner knee on the disc caliper [ however that may be on borrowed time !]
nice not to rub elbows on rear wheels as wheelbase has changed from 36" to 41"
luggage area is to big !!! by about 3-4" now if I cut and reweld the bustle to remove the excess it will have the same effect as moving the rear wheel back by the same distance. It will make the trike shorter AND move the load further over the rear wheels so improving the traction win win.
Ride seems better [ longer wheel base ] but to be honest that is subjective and 12 miles are not many !

regards Paul
And how were the brakes on this mammoth journey? God/Bad/Indifferent?
 
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hi all

So done a bustlectomy and taken 4" out of that , result ? made trike shorter by 4" which is the same as increasing the w/b by 4" so should improve front end traction as well. Win Win me thinks.

Downside well it will move the panniers further towards the seat and then there could be some conflict with the axle securing bolt , need to look at that when it is fully assembled again , Sunday with a bit of luck.

Then welded some more steel to the frame ?



The 2 wire parts nearest the camera are for the tent to - rest on & to strap it to .

Now the more observant of you will see that is becoming a bit of a pig in a poke adding stuff is creating a scenario where some of the steel is now redundant and there are far to many welds ! So much for forward planning :)

The lower wire frame and 2 braces could have been replaced by a C shape like behind the axle and the front vertical loop could have been replaced by 2 verticals ? reducing the steel used [ weight ] and welds down from 9 to 4 ! hey ho ....

Bring on Hindsight ;):)



Same goes for rear bustle ..

You can just see the internal sleeves I had to put in the axle holes that were made for the ' wheel chair ' versions that are 16mm and I am now using axles of 12mm instead.

regards Paul
 
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Paul,
That's looking very tidy and a nice sturdy frame that will last a long time I think.
If you really needed to pare the weight down for day-trips rather than carrying the whole camp a few cuts and some plates and you could make everything aft of rear axle line demountable and bolt on/off.
Leaving the small wire cage fwd of the line for a day bag to be fastened to.
Nice work mate!
 
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Paul,
That's looking very tidy and a nice sturdy frame that will last a long time I think.
Thanks , probably ploughing a lonely furrow ? as I don't remember any other Zombie trying to replace a trailer with trike mods ?

If you really needed to pare the weight down for day-trips rather than carrying the whole camp a few cuts and some plates and you could make everything aft of rear axle line demountable and bolt on/off.
Nearly ahead of me ;););)

I think I have tried to make a trailer attached to the trike , not really needed when camping as I already know the load and it consists purely of panniers and a tent.

As I try my best to use the trike instead of the car it's only around home and trips to supermarkets/DIY stores etc I really need a trailer sized hole and to be honest I already have a trailer for that ? [ although it does need assembling and adding this to a trike would be quicker ? ]



The red represents the Mk1 dead axle and rear vertical , if I attached 3 brackets where the yellow blobs are I could make the same frame as you say bolt on , then I could make a lighter simpler frame for day to day riding ?


Leaving the small wire cage fwd of the line for a day bag to be fastened to.
Nice work mate!
Hold that thought , although it won't quite work , panniers are taller than you think !



Maybe 14"-16" ? that inward frame is no higher than the tent show in this picture about 8" in non-metric money.

Anyway for this year we have finished fiddling and it needs testing and debugging pronto ...

regards Paul
 
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Well it is back together ...

Can you see the missing 4" ?

Before :-



After :-



.. and like the curates egg ?

Has some good parts ...

Tent goes here :-



May need some short pillars to stop the straps riding off the rod they are wrapped around.

Then tent and 2 panniers :-





then with tent and all 4 panniers :-



Ok still lots to do but progress is being made.

.. and has some bad parts ....

Brakes still pulsing/grabbing/snatching which every is your interpretation.

Swapped wheel and problem moves with wheel.

When spinning wheels and gently applying brakes ?

Good side - gentle but continuous rubbing sound

Bad side - rubbing sound again but on-off-on-off etc [ high spots ? ]

all for now Paul
 
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Bad wheel is out of round for sure.
You could slacken off all of the spokes fully so they are all loose and not under tension and see if the drum still grabs when it is spun.
This would tell you whether the drum is bent/ovalled or it was poor spoke tensions pulling it out.
Just a thought.You could measure the variance with a dial-gauge, before you do anything, then after slackening the spokes see if it alters?
Truing a wheel is no big job.
 
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Bad wheel is out of round for sure.
Seems like it.

You could slacken off all of the spokes fully so they are all loose and not under tension and see if the drum still grabs when it is spun.
This would tell you whether the drum is bent/ovalled or it was poor spoke tensions pulling it out.
Not yet , frustratingly despite having large quantities of 20" wheels in stock it is the ONLY wheel I can use on the trike , so if I start messing with it then there is no more testing/shake down rides until I have resolved the issue and that assumes it can be resolved.

Just a thought.You could measure the variance with a dial-gauge, before you do anything, then after slackening the spokes see if it alters?
Truing a wheel is no big job.
Would like to do this , non invasive testing , however in my mind I am unsure how to set the gauge up to measure the hub ?
Do I need to measure the inside surface ?
Would I see the out of true on the outside ?

regards Paul
 
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.. and viola and test ride.

Preparing for curry night ?



So 3 bags containing 18 toilet rolls each ...



Now this sort of load/trip is the reason I build a cage frame on the rear instead of a simple pannier/s rack ?

So success and now it is 4" shorter it is almost no extra length behind the rear wheels ?

onward and every horizontal Paul
 
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Do I need to measure the inside surface ?
Yes.
Stick a 12mm (or whatever the axle size is) bolt through it and set the dial gauge up on its multi-jointed holder to sit on the inside edge at as straight an angle as you can so it is as near vertical with the surface as possible in at least the radial plane (if that makes sense). Turn the wheel slowly without jolting it around and see how much the dial swings.
If you cannot do this (not tried it) then see if there is room to have it sit on the outside edge of the lip of the drum and measure there.
Good luck.

Fully understand the need to NOT ruin the test-bed. But loosening the spokes & re-truing wouldn't take long and would tell you at least something about what is causing the out of round very quickly.
10 mins to slacken the spokes.
5 mins to test if the bind is still there, or not.
60 mins to re-true the wheel (max).

HTH.
 
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